Denver Broncos linebacker Von Miller will be suspended at least six games for violating the NFL's substance-abuse policy, ESPN reported Monday. Miller was scheduled to meet with the league on Tuesday to appeal the looming suspension, which had been initially set at four games.

It's a huge blow for the AFC's best team, which is looking at being without its best defensive player for nearly half the season. Miller has 30 sacks in his first two seasons, and had 18 1/2 in 2012. He's the heart and soul of their front seven, and a key playmaker all over the field.

The Broncos won't have Miller for the first stretch of the season, beginning with a playoff rematch with the Super Bowl champion Baltimore Ravens at home in the season opener on Thursday, Sept. 5. His absence also includes a Week 2 game at the New York Giants and a Week 5 game at the Dallas Cowboys.

Behind Miller on the Broncos' depth chart is Shaun Phillips. Although Phillips, a one-time Pro Bowler, is coming over from nine fine seasons with the rival San Diego Chargers, his steady sack production came from the edge in the 3-4. It will be tough for him, at 32, eight years older than Miller, to have the same all-around impact outside in a 4-3.

In addition to being a top-flight young defender, Miller is also one of the league's most irreplaceable players.